JP2006226462A - Bearing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing structure, particularly, a bearing structure with a vibration damping material between a bearing outer ring and a supporting member, for improving the durability of a bearing. <P>SOLUTION: The bearing structure comprises the vibration damping material 2 arranged between a case member and a bearing outer ring portion 1 all over the periphery. The bearing outer ring portion 1 and the vibration damping material 2 have contact with each other at their non-circular faces. Since the bearing outer ring portion 1 and the vibration damping material 2 have contact with each other at their non-circular faces, a pressurized condition such as increased contact pressure is produced by suppressing the rotation of the vibration damping material 2. Thus, friction between the vibration damping material 2 and the bearing outer ring portion 1 is suppressed to improve the durability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing structure, and more particularly to a bearing structure in which a damping material is provided between a bearing outer ring and a support member.

Generally, the bearing is often fitted with a clearance between the bearing outer ring and the support member due to processing requirements. When the shaft rotates at a high speed, the bearing outer ring also rotates. Durability may decrease due to friction. In order to solve this problem, Patent Document 1 describes an invention in which the bearing case has a polygonal shape. Patent Document 2 describes an invention in which a pin for preventing rotation is attached to an outer ring and a notch is formed in a bearing box. Further, Patent Document 3 describes an invention in which the outer periphery of the bearing is threaded and the outer periphery of the housing is screwed.
Japanese Patent Publication No. 7-45887 JP 2004-239388 A Japanese Utility Model Publication No. 55-144224

  According to the inventions of Patent Documents 1 to 3, since the bearing case or the bearing outer ring is fixed, the bearing case or the bearing outer ring does not rotate, and it is possible to suppress a decrease in durability due to friction.

  On the other hand, when vibration is generated as the shaft rotates at high speed, in the inventions of Patent Documents 1 to 3, the vibration is transmitted to the casing from the portion where the bearing outer ring and the case or the housing are in close contact with each other. Even if a damping material is provided between the bearing outer ring and the case or housing in order to cut off the transmission of vibration, the damping property of the damping material is stress-dependent, so the stress applied to the damping material If it is small, there is a problem that the vibration control effect cannot be fully exhibited.

  The present invention has been made to solve the above technical problem, and an object thereof is to suppress a decrease in durability of the bearing.

  In order to achieve the above object, the present invention is configured to provide a vibration damping material between the housing and the bearing outer ring, and to suppress relative slip between the bearing and the housing. More specifically, according to the first aspect of the present invention, in the bearing structure in which the damping material is disposed between the case member and the bearing outer ring portion, the bearing outer ring portion and the damping material are in contact with each other on a non-arc-shaped surface. It is the bearing structure characterized by the above.

  The invention according to claim 2 is the bearing structure according to claim 1, wherein the non-arc-shaped surface is a part of a continuous curved surface having different curvature radii.

  Further, the invention of claim 3 is the invention of claim 1 or 2, wherein a groove is formed obliquely in the axial direction in a part of the non-arc-shaped curved surface of the damping material or the bearing outer ring portion, and The bearing structure is characterized in that the outer ring portion of the bearing or the damping material has a protrusion so as to be fitted into the groove.

  According to the first aspect of the present invention, the bearing outer ring portion and the damping material are in contact with each other on a non-arc-shaped surface. Therefore, since a pressurized state such as an increase in contact pressure occurs due to suppression of rotation of the damping material, friction between the damping material and the bearing outer ring portion is suppressed, and durability can be improved. .

  According to the invention of claim 2, the contact surface between the bearing outer ring portion and the damping material is configured as a continuous surface having different curvature radii. Therefore, rotation of the damping material is suppressed, and a pressurized state such as an increase in contact pressure occurs, so that friction between the damping material and the bearing outer ring portion is suppressed, and durability can be improved. .

  Furthermore, according to the invention of claim 3, the bearing outer ring portion is fixed by fitting the groove provided in the vibration damping material or the bearing outer ring portion with the protrusion provided in the bearing outer ring portion or the vibration damping material. The Since the bearing outer ring portion and the vibration damping material are configured with non-arc-shaped surfaces, the bearing outer ring does not rotate, and a pressure is applied from the bearing outer ring portion to the vibration damping material as the shaft rotates. Stress is generated in the damping material. Since the damping material increases the damping capability when the stress increases, the damping effect can be increased.

  Next, the present invention will be described based on specific examples. FIG. 1 is a sectional view in a direction perpendicular to the shaft of a bearing to which the present invention is applied. The bearing 8 includes a bearing inner ring 6, a bearing outer ring 1, a bearing 7, and a vibration damping material 2, and the bearing inner ring 6 is provided on the innermost side. The bearing inner ring 6 rotates integrally with a shaft supported by the bearing 8. The bearing inner ring 6 is supported on the bearing outer ring 1 by a plurality of bearings 7. That is, a plurality of bearings 7 are arranged between the bearing inner ring 6 and the bearing outer ring 1.

  Further, a damping material 2 is provided between the bearing outer ring 1 and a case or housing that supports the bearing 8. The surface of the bearing outer ring 1 in contact with the bearing 7 is formed in a perfect circle, but the surface 5 of the bearing outer ring 1 in contact with the vibration damping material 2 is formed in an elliptical shape. It is formed in a shape.

  When the bearing outer ring 1 is formed in a perfect circle shape, the bearing outer ring 1 and the vibration damping material 2 are clearance fits from the viewpoint of bearing durability, so the bearing outer ring 1 also rotates as the shaft rotates. Therefore, there is a problem that friction is generated between the damping material 2 and the bearing outer ring 1 and durability is lowered.

  On the other hand, in the present invention, since the bearing outer ring 1 and the damping material 2 are in contact with each other with an elliptical surface, even if a torque is generated to rotate the bearing outer ring 1 as the shaft rotates. The bearing outer ring 1 does not rotate. Therefore, it is possible to suppress a decrease in durability without causing friction.

  Further, since the rotation of the damping material 2 is fixed, when a torque for rotating the bearing outer ring 1 is generated with the rotation of the shaft, a pressure is applied to the damping material 2, and the damping material 2 is stressed. As shown in FIG. 4, the damping material, that is, the damping coefficient, that is, the damping capacity increases as the applied stress, that is, the strain increases, so that the damping characteristics of the damping material 2 can be improved.

  Further, for the purpose of increasing the damping capacity of the vibration damping material, stress may be positively applied to the vibration damping material. FIG. 2 is a diagram showing an example in which stress is positively applied to such a vibration damping material. The damping material 2 and the bearing outer ring 1 are formed in an elliptical shape as in FIG. 1, but a groove 3 is provided in a part of the damping material 2, and one of the bearing outer rings 1 is formed. Protrusions 4 that mesh with the grooves 3 are provided at the portions. Moreover, the groove | channel 3 is provided so that it may become diagonal toward the thickness direction of a bearing, as shown to (b) of FIG.

  As shown in FIG. 2B, the convex portion 4a is pressed against the groove wall portion 3a by the movement accompanying the rotation of the bearing outer ring 1. When the movement of the bearing outer ring 1 further proceeds, the convex portion 4 becomes the position of the convex portion 4b. That is, the bearing outer ring 1 moves in the direction opposite to the rotational direction applied from the shaft. Therefore, stress is applied to the bearing outer ring 1 in the twisting direction. On the other hand, since the movement of the bearing outer ring 1 does not occur while the convex part 4 is pressed against the groove wall part 3a, the degree of adhesion between the bearing outer ring 1 and the damping material 2 increases, and the torsion of the bearing outer ring 1 The generated stress is transmitted to the vibration damping material 2. Accordingly, since a greater stress is applied to the damping material 2, the damping capacity of the damping material can be increased.

  In order to suppress the rotation of the bearing outer ring 1, the bearing outer ring 1 may have a polygonal shape as shown in FIG. Moreover, in the said Example, although the shape of the bearing outer ring | wheel 1 and the damping material 2 was made into the ellipse, the bearing outer ring | wheel 1 and the damping material 2 are contacting in the non-arc-shaped surface, The non-arc-shaped surface May be a part of a continuous surface having a different radius of curvature. Further, in the above embodiment, the convex portion 4 is provided on the bearing outer ring 1 and the groove 3 is provided on the vibration damping material 2, but this is provided with the groove 3 on the bearing outer ring 1 and the convex portion on the vibration damping material 2. Also good.

It is a figure which shows the bearing structure which made the bearing outer ring | wheel and the damping material the ellipse. It is a figure which shows the bearing structure which provided the groove | channel in the bearing outer ring | wheel and the protrusion in the damping material. It is a figure which shows the bearing structure which made the bearing outer ring polygonal. It is a graph showing the relationship between the distortion of a damping material, and a damping coefficient.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bearing outer ring part, 2 ... Damping material, 3 ... Groove, 4 ... Convex part.

Claims (3)

In the bearing structure in which the damping material is disposed between the case member and the bearing outer ring portion,
A bearing structure, wherein the bearing outer ring portion and the damping material are in contact with each other on a non-arc-shaped surface.   The bearing structure according to claim 1, wherein the non-arc-shaped surface is a part of a continuous curved surface having different curvature radii.   A part of the non-arc-shaped curved surface of the damping material or the bearing outer ring part is formed with a groove obliquely in the axial direction, and a protrusion is provided on the bearing outer ring part or the damping material so as to fit in the groove. The bearing structure according to claim 1, wherein the bearing structure is provided.

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